#include "OgreStableHeaders.h"

#include "OgreDynLib.h"

#include "OgreException.h"
#include "OgreLogManager.h"

#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX // required to stop windows.h messing up std::min
#include <windows.h>
#endif

#if OGRE_PLATFORM == OGRE_PLATFORM_APPLE || OGRE_PLATFORM == OGRE_PLATFORM_IPHONE
#include "macUtils.h"
#include <dlfcn.h>
#endif

namespace Ogre
{
	//-----------------------------------------------------------------------
	DynLib::DynLib(const String& name)
	{
		mName = name;
		m_hInst = NULL;
	}

	//-----------------------------------------------------------------------
    DynLib::~DynLib()
    {
    }
	
	//-----------------------------------------------------------------------
	void DynLib::load()
	{
		// Log library load
        LogManager::getSingleton().logMessage("Loading library " + mName);

		String name = mName;
#if OGRE_PLATFORM == OGRE_PLATFORM_LINUX
		// dlopen() does not add .so to the filename, like windows does for .dll
		if (name.substr(name.length() - 3, 3) != ".so")
			name += ".so";
#elif OGRE_PLATFORM == OGRE_PLATFORM_APPLIE
		// dlopen() does not add .dylib to the filename, like windows does for .dll
        if (name.substr(name.length() - 6, 6) != ".dylib")
			name += ".dylib";
#elif OGRE_PLATFORM == OGRE_PLATFORM_WIN32
		// Although LoadLibraryEx will add .dll itself when you only specify the library name,
		// if you include a relative path then it does not. So, add it to be sure.
		if (name.substr(name.length() - 4, 4) != ".dll")
			name += ".dll";
#endif

		m_hInst = (DYNLIB_HANDLE)DYNLIB_LOAD(name.c_str());

		if (!m_hInst)
			OGRE_EXCEPT(
                Exception::ERR_INTERNAL_ERROR, 
                "Could not load dynamic library " + mName + 
                ".  System Error: " + dynlibError(),
                "DynLib::load" );
	}

	//-----------------------------------------------------------------------
	void DynLib::unload()
	{
		// Log library unload
        LogManager::getSingleton().logMessage("Unloading library " + mName);

		if (DYNLIB_UNLOAD(m_hInst))
		{
			OGRE_EXCEPT(
                Exception::ERR_INTERNAL_ERROR, 
                "Could not unload dynamic library " + mName +
                ".  System Error: " + dynlibError(),
                "DynLib::unload");
		}

	}

	//-----------------------------------------------------------------------
	void* DynLib::getSymbol( const String& strName ) const throw()
    {
        return (void*)DYNLIB_GETSYM( m_hInst, strName.c_str() );
    }

	//-----------------------------------------------------------------------
	String DynLib::dynlibError(void)
	{
#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
		LPVOID lpMsgBuf; 
        FormatMessage( 
            FORMAT_MESSAGE_ALLOCATE_BUFFER | 
            FORMAT_MESSAGE_FROM_SYSTEM | 
            FORMAT_MESSAGE_IGNORE_INSERTS, 
            NULL, 
            GetLastError(), 
            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), 
            (LPTSTR) &lpMsgBuf, 
            0, 
            NULL 
            );
		String ret = (char*)lpMsgBuf;
		// Free the buffer
		LocalFree(lpMsgBuf);
		return ret;
#elif OGRE_PLATFORM == OGRE_PLATFROM_LINUX || OGRE_PLATFORM == OGRE_PLATFORM_APPLE
		return String(dlerror());
#else
		return String("");
#endif
	}

}
